I guess this was designed to be put into token decks, much like Lord of the Pit , but these days this card would be laughable at best even at common status. Trample ain't all that good on a 4/4, and not being able to untap is -crippling-. There are much better alternatives, and if you absolutely positively MUST have trample on a black creature, just use Unnatural Predation.

This is really not that bad if you have something to spit out tokens, or playing with Instill Energy. Every black trampler has some sort of drawback and this one is pretty easy to work around. 4/4 isn't much, but suddenly Howl From Beyond, Endless Scream find an interesting use. You could do a lot worse as a method to try and get through a line of chump blockers, though you'd likely just as soon get rid of them the old-fashioned way.

At worst, this is one of the most playable Homelands cards, whatever that says for it.

Kao is pretty right... whatever the crappiness of the rest of the creature is, "sac a creature: untap this" with no mana cost is a pretty good combo enabler. The upkeep restriction may or may not be a real factor depending on what your combo is.

Actually I went to this page after seeing the preview of Grimgrin, Corpse-Born (it'll link somewhere fairly soon) after first being really disappointed in the harsh drawback (maybe it's still good with the auto kill on attack? Not sure, but it's not hopeless) and then realizing that "sac: untap this" could be very abusable. So I did a search for similar clauses and wow, a Homelands card beat you to it. Of course, each fuffils a different niche for combos; the upkeep restriction may or may not matter on certain combos, while the double black vs. blue black also depends on what you're doing. And of course Grimgrin has a built in point to going infinite.

"The Black Carriage is Baron Sengir's favorite way to tour through the Sengirian countryside. When Baron Sengir wishes to ride, he chooses a villager to act as Coachman. When the tour of his lands and properties is complete, the Baron personally unbridles his steeds and lets them consume the terrified peasant as reward for their labor. Careening along the cobbleroads at breakneck steeds, the Baron's chargers have been seen to sweat fire and blood, and that when they gallop their horseshoes throw fiery sparks."
-The homelands document